Topband: Any Linrad selective limiter noise blanker experts here?

Jim Brown jim at audiosystemsgroup.com
Tue Jan 21 13:30:05 EST 2020


On 1/20/2020 2:28 PM, Richard (Rick) Karlquist wrote:
> In most cases, line noise is a repeating function with a frequency of
> 50 or 60 Hz.  To make an  effective noise blanker in a contest, you
> simply have to make a filter that only responds to harmonics of the
> line frequency and then generate the inverse function from a 50 or
> 60 Hz line clock.

Unfortunately, that's too simple. For effective cancellation, that 
inverse function must be precisely in phase (degrees, not polarity) and 
equal in amplitude at each harmonic frequency.

73, Jim K9YC


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